Rearrangement of penicillins to penicillenic acids and the reactions of the penicillenic acids in solution will be further analyzed. The possibility of cephalosporins undergoing rearrangement analogous to the penicillenic acid rearrangement will be investigated. Effects of x-rays on intracellular pH and glycolytic mechanisms in Ehrlich tumor cells will be studied. Effects of a ketogenic diet on intracellular pH of mouse brain will be studied. Liver dihydropyrimidinase will be purified and its identity as the enzyme causing hydrolytic ring opening of 5-phenylhydantoin and alpha- phenylsuccinimide investigated. Other drugs will be studied as possible substrates of this enzyme. Model compounds will be synthesized to ascertain what structural features are essential for susceptibility as a substrate.